The invention relates to power transmission belts and more particularly to power transmission belts having a layer spliced with a non-woven backing material.
It is well known in the art to adhesively bond a cover layer to an outer surface of a power transmission belt in order to reinforce the belt. The layer may comprise fabric. The cover layer is laid under successive layers as the belt is fabricated on a mandrel. The ends of the layer are joined together to define the endless layer on the belt build.
The cover layers may also comprise other materials such as rubber coated fabrics or fiber loaded sheet materials. These are often bias cut and re-oriented to optimize flex and support characteristics in the finished product. The sheets are re-attached after the change in orientation by either overlapping and adhering their edges or by butting and sewing the edges together or butting and thermally splicing the edges together. The overlapped material can cause thickness irregularities in the product that result in rough running or noisy belt operation. The sewn edges avoid most of the thickness problems, but are generally more costly to make.
Another method can involve application of a fusible strip spanning between the ends of the cover layer. This method requires a fusible strip to be applied and heated at a vulcanizing or melting temperature. This again can cause thickness irregularities in the belt.
Representative of the art is EP patent 0 742 383 B1 which discloses a belt having a laminate comprising a fabric sheet and an adhesion rubber sheet. The ends of the laminate are butt spliced together by seaming or thermal setting.
Another representative of the art is U.S. Pat. No. 5,224,905 (1993) to Mishima which discloses a belt having a uniform cross-sectional configuration along its entire length and having a fabric layer that is butt-spliced together. The butt-splice is accomplished by sewing or by using an overlapping material comprising a thermo-plastic resin.
What is needed is a belt having a spliced cover layer using a non-woven strip. What is needed is a belt having a butt-spliced cover layer using a non-woven strip on a surface of the adjoining ends. What is needed is a belt having a butt-spliced layer using a non-woven strip having a thickness substantially less than the thickness of the attached ply. What is needed is a belt having a spliced single cover layer using a non-woven strip whereby belt noise and vibration is reduced. The present invention meets these needs.
The primary aspect of the invention is to provide a belt having a spliced layer using a strip comprising non-woven material.
Another aspect of the invention is to provide a belt having a butt-spliced layer using a strip comprising non-woven material on a surface of the adjoining ends.
Another aspect of the invention is to provide a belt having a butt-spliced layer using a non-woven strip having a thickness substantially less than the thickness of the attached ply.
Another aspect of the invention is to provide a belt having a spliced single cover layer using a non-woven strip whereby belt noise and vibration is reduced.
Other aspects of the invention will be pointed out or made obvious by the following description of the invention and the accompanying drawings.
The invention comprises a power transmission belt having a compression section, a load carrying section and an outer layer. The outer cover layer comprises a fabric layer or fiber loaded stock for reinforcement. The cover layer is butt-spliced together using a non-woven strip of material spanning across the butted ends of the cover layer. The thin strip used in the splice significantly reduces belt noise.